fix: update subscription.go with external name handling for observe i… (#486)

* fix: update subscription.go with external name handling for observe imports

* chore: add test for new changes

* fix: update code to be complain to external-name adr

---------

Co-authored-by: sdischer-sap <stephan.discher@sap.com>

Author: SatabdiG

internal/controller/account/subscription/subscription.go

@@ -129,6 +129,20 @@ func (c *external) Observe(ctx context.Context, mg resource.Managed) (managed.Ex
 	if !ok {
 		return managed.ExternalObservation{}, errors.New(errNotSubscription)
 	}
+	externalName := meta.GetExternalName(cr)
+	if externalName == cr.Name {
+		// Set correct external-name format for import/observe scenarios
+		if isObserveOnly(cr) && cr.Spec.ForProvider.AppName != "" && cr.Spec.ForProvider.PlanName != "" {
+			expectedExternalName := fmt.Sprintf("%s/%s", cr.Spec.ForProvider.AppName, cr.Spec.ForProvider.PlanName)
+			return managed.ExternalObservation{}, errors.Errorf(
+				"For Observe-only Subscriptions, external-name must be set to 'appName/planName' format. "+
+					"Found: '%s'. Expected: '%s'. "+
+					"Please set the annotation: crossplane.io/external-name: \"%s\"",
+				externalName, expectedExternalName, expectedExternalName,
+			)
+
+		}
+	}
 
 	apiRes, err := c.loadSubscription(ctx, cr)
 	if err != nil {
@@ -260,3 +274,18 @@ func (c *external) shouldRecreateOnFailure(cr *v1alpha1.Subscription, apiRes *su
 	}
 	return false
 }
+
+func isObserveOnly(cr *v1alpha1.Subscription) bool {
+	if len(cr.Spec.ManagementPolicies) == 0 {
+		return false // default is full management
+	}
+	for _, policy := range cr.Spec.ManagementPolicies {
+		if policy == xpv1.ManagementActionCreate {
+			return false // allowed to create
+		}
+		if policy == xpv1.ManagementActionAll {
+			return false // allowed to create
+		}
+	}
+	return true // only Observe/Update/Delete, no Create
+}

internal/controller/account/subscription/subscription_test.go

@@ -167,6 +167,35 @@ func TestObserve(t *testing.T) {
 				}), WithExternalName("name1/plan2")),
 			},
 		},
+		"ObserveOnly_RequiresCorrectExternalNameFormat": {
+			reason: "Observe-only resource with default external-name should return validation error",
+			args: args{
+				cr: NewSubscription("test-subscription",
+					WithData(v1alpha1.SubscriptionSpec{
+						ForProvider: v1alpha1.SubscriptionParameters{
+							AppName:  "sapappstudio",
+							PlanName: "standard-edition",
+						},
+					}),
+					WithManagementPolicies(xpv1.ManagementActionObserve),
+					WithExternalName("test-subscription"), // Wrong - equals metadata.name
+				),
+			},
+			want: want{
+				o:   managed.ExternalObservation{},
+				err: errors.New("For Observe-only Subscriptions, external-name must be set to 'appName/planName' format. Found: 'test-subscription'. Expected: 'sapappstudio/standard-edition'. Please set the annotation: crossplane.io/external-name: \"sapappstudio/standard-edition\""),
+				cr: NewSubscription("test-subscription",
+					WithData(v1alpha1.SubscriptionSpec{
+						ForProvider: v1alpha1.SubscriptionParameters{
+							AppName:  "sapappstudio",
+							PlanName: "standard-edition",
+						},
+					}),
+					WithManagementPolicies(xpv1.ManagementActionObserve),
+					WithExternalName("test-subscription"),
+				),
+			},
+		},
 	}
 	for name, tc := range tests {
 		t.Run(name, func(t *testing.T) {
@@ -681,3 +710,54 @@ func WithRecreateOnSubscriptionFailure() SubscriptionModifier {
 		r.Spec.RecreateOnSubscriptionFailure = true
 	}
 }
+
+func TestIsObserveOnly(t *testing.T) {
+	tests := map[string]struct {
+		managementPolicies []xpv1.ManagementAction
+		expected           bool
+	}{
+		"ObserveOnly": {
+			managementPolicies: []xpv1.ManagementAction{xpv1.ManagementActionObserve},
+			expected:           true,
+		},
+		"AllActions": {
+			managementPolicies: []xpv1.ManagementAction{xpv1.ManagementActionAll},
+			expected:           false,
+		},
+		"IncludesCreate": {
+			managementPolicies: []xpv1.ManagementAction{xpv1.ManagementActionObserve, xpv1.ManagementActionCreate},
+			expected:           false,
+		},
+		"ObserveAndUpdate": {
+			managementPolicies: []xpv1.ManagementAction{xpv1.ManagementActionObserve, xpv1.ManagementActionUpdate},
+			expected:           true,
+		},
+		"EmptyDefault": {
+			managementPolicies: []xpv1.ManagementAction{},
+			expected:           false,
+		},
+		"NilDefault": {
+			managementPolicies: nil,
+			expected:           false,
+		},
+	}
+
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			cr := &v1alpha1.Subscription{
+				Spec: v1alpha1.SubscriptionSpec{},
+			}
+			cr.Spec.ManagementPolicies = tc.managementPolicies
+			got := isObserveOnly(cr)
+			if got != tc.expected {
+				t.Errorf("isObserveOnly() = %v, want %v", got, tc.expected)
+			}
+		})
+	}
+}
+
+func WithManagementPolicies(policies ...xpv1.ManagementAction) SubscriptionModifier {
+	return func(r *v1alpha1.Subscription) {
+		r.Spec.ManagementPolicies = policies
+	}
+}